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Formula CFM to horse power?
Need a simple formula for air CFM moving through a pipe to mechanical work, horse power? There are some formulas used with wave power for CFM of air, so this might be a good place to start.
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Thank you for the information, but something seems off. In your calculation, as the efficiency of the turbine goes down it produces a higher HP? Shouldn't it be the other way around? Can you explain this and the 144 and 33000? Thanks
1hp = 33,000 ft-lb/min
1sq.ft = 144 sq.in.
Put the conversion factors in, then cross out all the units, you're left with only HP.
I thinks that's what 89FLHS is saying.
ee-HP-conversion.jpg
1sq.ft = 144 sq.in.
Put the conversion factors in, then cross out all the units, you're left with only HP.
I thinks that's what 89FLHS is saying.
ee-HP-conversion.jpg
The efficiency factor goes at the end. So 95% efficiency should be _multiply_ by 0.95, not divide by.
( (40*125*144)/33000 ) *0.95=20.7HP
That 33,000 conversion factor is 3.30x10^4, not 3.3000. So no need to carry too many decimal places in your final HP rating.
I think the number is actually 33,013 ft-lb/min per horsepower.
( (40*125*144)/33000 ) *0.95=20.7HP
That 33,000 conversion factor is 3.30x10^4, not 3.3000. So no need to carry too many decimal places in your final HP rating.
I think the number is actually 33,013 ft-lb/min per horsepower.
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To be more accurate you will need to include the mechanical efficiency of your apparatus. For instance, if you are using the air to spin a turbine, the turbine blade will not be one hundred percent efficient. A certain volume of air will pass the turbine without transferring its energy into rotary motion. To include efficiency in the formula, multiply the 33000 in the denominator by the efficiency as a decimal.
Example: 40 CFM at 125 PSI, mechanical efficiency 95% (40*125*144)/(33000*.95)=2